5、 写入数据：添加一个供应商CompanyNameCCNU添加该供应商的一个产品ProductName CCNU Soya-bean milk写入数据库并查看是否成功

INSERT INTO Suppliers (CompanyName) VALUES ('CCNU'); INSERT INTO Products (ProductName, SupplierID) VALUES ('CCNU Soya-bean milk', (SELECT SupplierID FROM Suppliers WHERE CompanyName = 'CCNU'));

SELECT * FROM Suppliers WHERE CompanyName = 'CCNU'; SELECT * FROM Products WHERE ProductName = 'CCNU Soya-bean milk';

如果成功，应该会返回一个包含新添加的供应商和产品的记录。